Add num_disks into stat

Signed-off-by: Xiaoxi Chen <[email protected]>

conanfile.py

@@ -9,7 +9,7 @@
 
 class HomeObjectConan(ConanFile):
     name = "homeobject"
-    version = "2.1.15"
+    version = "2.1.16"
 
     homepage = "https://github.com/eBay/HomeObject"
     description = "Blob Store built on HomeReplication"

src/lib/homestore_backend/heap_chunk_selector.h

@@ -151,6 +151,18 @@ class HeapChunkSelector : public homestore::ChunkSelector {
 
     uint32_t get_chunk_size() const;
 
+    /**
+     * @brief Returns the number of disks we seen
+     *
+     * Warning : calling this before HS fully start might getting wrong result.
+     *
+     * This function returns the number of disks the chunk selector seen.
+     * It should be the accurate source that how many disks in the system for data.
+     * If a disk is down in degraded mode, it wont be load and no chunk will be
+     * added into selector.
+     */
+    uint32_t total_disks() const { return m_per_dev_heap.size(); }
+
 private:
     void add_chunk_internal(const chunk_num_t, bool add_to_heap = true);
 

src/lib/homestore_backend/hs_homeobject.cpp

@@ -313,6 +313,7 @@ HomeObjectStats HSHomeObject::_get_stats() const {
 
     stats.num_open_shards = num_open_shards;
     stats.avail_open_shards = chunk_selector()->total_chunks() - num_open_shards;
+    stats.num_disks =  chunk_selector()->total_disks();
     return stats;
 }
 

src/lib/homestore_backend/tests/test_heap_chunk_selector.cpp

@@ -152,6 +152,8 @@ TEST_F(HeapChunkSelectorTest, test_for_each_chunk) {
     ASSERT_EQ(size.load(), 18);
 }
 
+TEST_F(HeapChunkSelectorTest, test_total_disks) { ASSERT_EQ(HCS.total_disks(), 3); }
+
 TEST_F(HeapChunkSelectorTest, test_identical_layout) {
     const homestore::blk_count_t count = 1;
     homestore::blk_alloc_hints hints;